Welder Dave
Senior Member
I was wondering if a 10-30 TO4 oil could help prevent slipping in some gears over using a straight 10 weight oil? Also can oil that may need to be changed cause slipping? My track loader calls for 30W but the shop said 10-30 would work better for different temps. The grader with an 8400 transmission calls for 10W. Originally called for ATF but they discovered fairly soon that ATF caused slipping when warm. They also had improved clutch plates for the trans. I know the oil and filter has been changed since new. Probably several times. Not sure if the trans. has ever been worked on but a couple bolts are missing for the trans. guard so I'd guess it has some work done to it. Mostly wondering how much difference new or different oil could make? Is synthetic any advantage in an older transmission?